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Research Focuses on the Dietary Benefits of Beef
Elements in beef have garnered interest in the scientific community, including conjugated linoleic acid (CLA) and selenium. CLA, a fatty acid found naturally in beef and dairy products, exhibits a number of benefits including tumor reduction. Selenium has shown potentially powerful antioxidant properties in animal studies. Trials are currently underway to confirm beneficial effects in humans.
The role of CLA in cancer prevention has been found to be more powerful than any other fatty acid in its ability to prevent formation and slow the growth of tumor development.1 Animal studies have found that CLA can inhibit malignant melanoma, colorectal, breast, ovarian and lung cancers in experimental animals.2,3,4,5,6
In animal studies, CLA reduced the risk of heart disease. In these models, LDL cholesterol and triglycerides dropped among CLA-fed subjects.7
CLA also appears to influence body fat levels. Several animal studies have noted that CLA induces a decrease in body fat and an increase in lean muscle. Trials are currently underway to confirm benefits for humans.8,9,10,11
CLA was found to prevent diabetes in animal models. Preliminary results suggest CLA helps normalize or reduce blood glucose levels and could possibly prevent adult-onset diabetes in humans.12
Beef is also a good source of selenium, providing 29.5 percent of the 1989 RDA for women and 23.1 percent for men.13 Recent studies have found that selenium may reduce the risk of heart disease and certain types of cancer such as prostate and enhance the body's ability to fight infections.14
1. Ip,C; Scimeca JA; Thompson HJ. Conjugated linoleic acid. A powerful anticarcinogen from animal fat sources. Cancer. 74:1050-1054; 1994.
2. Parodi, PW. Milk fat conjugated linoleic acid: can it help prevent breast cancer? Proceed. Nutr. Soc. New Zealand. 22:137-149; 1997.
3. Schultz, TD. Et al. Inhibitory effect of conjugated dienoic derivatives of linoleic acid and b-carotene on the in vitro growth of human cancer cells. Cancer Letters. 63: 125-133; 1992.
4. Schonberg, S. Krokan, HE. The inhibitory effect of conjugated dienoic derivatives (A) of linoleic acid on the growth of human tumor cell lines is in part due to increased lipid peroxidation. Anticancer Research. 15:1241-1246; 1995.
5. Visonneau, S. Et al. Effect of different concentrations of conjugated linoleic acid (CLA) on tumor cell growth in vitro. FASEB J. 9:A869; 1996.
6. Yoon, CS. Et al. Inhibitory effect of conjugated linoleic acid on in vitro growth of human hepatoma. FASEB J. 11:A578; 1997.
7. Lee KN, Kritchevsky D, Pariza MW. Conjugated linoleic acid and atherosclerosis in rabbits. Atherosclerosis. 108:19-25; 1994.
8. Doyle E. Scientific forum explores CLA knowledge. INFORM 9(1):69-73, 1998.
9. Park Y, Albright KJ, Liu W, Storkson JM, Cook ME, Pariza MW. Effect of conjugated linoleic acid on body composition in mice. Lipids. 32:853-858; 1997.
10. West DB, Delany JP, Camet PM, Blohm F; Truett AA, Scimeca J. Effects of conjugated linoleic acid on body fat and energy metabolism in the mouse. Am J Physiol. 44:R667-R672; 1998.
11. Cook ME, Jerome DL, Buege DR, Russell RL, Crenshaw TC, Storkson J, Albright K, Liu W, Park Y, Pariza MW, Scimeca JA, Lofgren P, Hentges E. Conjugated linoleic acid (CLA) reduces backfat thickness, increases percent lean and improves feed efficiency in pigs. Food Research Institute, Univ Wisconsin, 1997 Annual Mtg (poster abstr); 1997.
12. Houseknecht KL, Vanden Heuvel JP, Moya-Camarena SY, Portocarrero CP, Peck LW, Nickel KP, Belury MA. Dietary conjugated linoleic acid normalizes impaired glucose tolerance in the Zucker diabetic fatty fa/fa rat. Biochem Biophys Res Commun. 244;678-682;1998.
13. Zhang C, Shi B, Spallholz JE. The selenium content of selected meats, seafoods and vegetables. Trace Element Res. 39:161-169; 1993.
14. Oldfield JE. Some implications of selenium for human health. Nutr Today 26(4):6-11; 1991.
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